Gas mask



L. M. M BRIDE Oct. 1 1929.

GAS MASK asheet-sneet Oct. 1, 1929. L, M; MB RlDE 1,730,227

GAS MASK Filed March 51, 1.923 3 Sheets-Sheet 2 Oct. 1, 1929. M. McBRlDE 1,730,227

GAS MASK Filed March 31, 1925 3 Sheets-Sheet 3 I attonmq Patented Oct. 1, 1929 UNITED STATES V'PATTENT OFFICE LEWIS M. MCBRIDE, OF WASHINGTON, DISTRICT OF COLUK B IA i GAS mas]:

Application filed March 31, 1923. Serial No. 628,990.

' wherein the canister may be'readily refilled with the air purifying agent thereby permitting the ready renewal of the chemicals; also I wherein is provided a self-contained speaking gas mask of minimum size and weight, whether with or without valves, thereby eliminating the usual canister carrying caseand appended breathing tube; also wherein is provided a canister having no interior contained valves or parts subject to deterioration other than the chemical ingredients; also 29 wherein inhalations may be through the canister and exhalations through a valve outlet Without passing through ,the canister; also wherein the mask may be readily transformed from a self contained type to the usual breathing tube type, and'vice versa, without alteration in the face-piece 'of the mask; also wherein the inflowing purified air from the' canister into the face-piece is deflected in the direction of the eye-pieces or lenses.

To the accomplishment of the foregoing and such other objects as may hereinafter appear the, inventionconsists in the features hereinafter particularly described and then sought to be clearly defined by the claims, ,reference being had to the accompanying drawings forming a part hereof, and in which Figure 1 is a perspective view of the mask face-piece, with portions broken away, and

embodying'features of the invention;

. 4 and chamber;"with portions of the chamber wall and diaphragm broken away;

Figure t is a vertlc'al sectlon through a pertions;

proved type or form of construction.

Figure 2 is a vertical section through the ister and having a flutter valve for the exhala- Figure 5 is-an end view of Figure 4, with a portion of the wall of the valve chamber and seat broken away; Figure 6 is a vertical section through a canister of varying cross diameters, or step-down formation; 1 Q Figure 7 is an end view of Figure 6; V Figure 8 is a vertical section through a no canister of bell-shape or flaring type; Figure 9' is a perspective of a face-piece of (a modified formof mask'for connection with a canister of ordinary type;

Figure 10 is a vertical section through the speaking tube of the mask illustrated in Figure 9, with means for attachment to the diaphragm air chamber of the mask;

Figure 11 is a view showing one end of the respirator shell provided with a detachable screw cap. V In the drawings the numeral 1 designates a mask face-piece which may be of any ap- The face-piece has attached in any suitable manner a threaded annular metal ring 2 placed oppositeto the position of the mouth of the wearer. This ring is formed with an interior annular chamber 3 tojreceive air passing from a canister hereinafter described,'80 i to support from theface-piece what for convenience 'I will designate a combined respi- 'rator and speaking tube. This comprises a double walled casing, preferablycylindrical inform, having an outer chamber 7 which may contain the cheniieal substanceS designed to purify the air that is inhaled through the respirator, or canister,a'nd an inner cham tion of the canister and canister-receiver and g ber or tube 9 which serves for the transmis face-piece, illustrating the diaphragm of a sion of speech or voice waves. form to prevent exhalations through the can-' The outer end wall 10 and'the innerend wall 11 of ehamv wise open end of the voice chamber or tube9,

there is placed a diaphragm 12 of suitable ma-r 10 terial impervious to gas but capable of vibration, to a greater or less extent, under the 'im ulse of Voice waves. This diaphragm is he (1 in space against its seat 4 by pressure of the end wall of chamber 8 thereagainst when 5 the'respirator is positioned in the retaining ring 2 of the face-piece, and the peripheral edge of the diaphragm in some instances may be stifi'ened by an annular, wire to form a bead 13E and the respirator may be held in the re- 2 taining ring of the face-piece by external threads on the respiratorlengaging the threads I of the ring, as illustrated, or otherwise. It is referred to place in each end of the chemical holding chamber 8 of the respirator fine mesh screens 14 of suitable material to prevent escape or leakage of the chemical substance if it be of a fine granulated or pulverulent character. The respirator may be of the form illustrated in Figures 2, 6, or 8 as desired; the form shown in Figure 6 having difierent diameters, or' stepped down, and thatshown in Figure 8 being bell-sha ed or flaring in formation so. as to increase t e volume or clearness of the voice waves emitted as through the speaking tube. In the form illustrated in Figures-1 to 3 the inhalations as well as the exhalations are through the chemical containing chamber 8." In Figures 4 and I have illustrated a variation in which the inhalations are through the chemical containing chamber 8 but the exhalations' are from the chamber 3 through what- I term a flutter valve, that is, a valveithat opens sufficiently under the pressure of exhalations andimmediately closes or collapses under inhalations so as to prevent gases entering the air chamber 3 andv from thence into the mask. This is effected by usinga gas imperviousdiaphragm of larger diameter than the pre- 1 viously described diaphragm so that the portion of the diaphragm. which extends-beyond its seat will constitute a flap-valve 16 which will overlie the openings in the adjacent end of the chemical containing chamber 8 so as to uncover the openings in inhaling through ..the chemical chamber as indicated in Figure 4 and close said openings in exhaling. In this case exhalations will be from chamber 3 through the flutter-valve-17. .which will be of rubber or equivalent material, preferably of the form illustrated, with its edges slitted,"

' for instance as indicated at'17, and which [will communicate through a tube or nipple 18, or otherwise, with the chamber 3. It will be observed that while this flutter-valve is in communication with the chamber 3 it is en- .tirely outside thereof and also. outside of the mask so that voice transmission will not be impaired by disturbances created by presence of the valve within the face-piece or. mask.

Being entirely outside of the mask it will not -cause such disturbing influences.

In Figures 9 and 10, I have illustrated a maskcontai'ning some of the features of my invention with a modification adapting the I features to, be 'used' in connection with. a'gas canister of ordinary construction. In this form the air purifying chemical is omitted from therespirator and the latter' will be connected by a flexible tube 19 with a chemical containing canister of ordinary construction adapted as usual to be attached to the body of the wearer. In this instance the respirator I will have the voice or speaking tube 9 and the gas impervious diaphragm 15' and .flutter-' 5 I Valve 17 as described for the form illustrated in Figures 4 and 5, and the chamber 7 instead of containing a chemical will be made to communicate with a ascanister of ordinary construction throug a nipple 20 leading .from p I the chamber 7 and the flexible conducting or breathing tube 19 the outer end of the chamber being closed except for thenipple 20 open- .ing into the chamber. The respirator will be coupled to the respirator retaining ring 21 of a5 the mask by a loose-fittin threaded ring 21 engaging the threads of t e' ring 2 and provided with a knurled flange or collar 22 for its manipulation,--the other end of the loosefitting ring having a bearing against .a circu- .100

lar boss or shoulder 23formed on the end of j 'the respirator shell with a suitable packing 24 interposed between the end of the ring and shoulder to form a packed joint at that point,

if desired. This loose-fitting coupling ring 1 enables the respirator shell to be coupled tothe respirator retaining ring of the face-piece ofthe mask without turning the respirator shell and consequently prevents twisting ofthe connecting or'breathing tube which leads 11o I from the canister. In this form the respirations' are through the breathing tubeleading from the ordinary canister and through the chamber 7. of the res irator and the chamber.

3 into the mask, w He the exhalations are 116 through the chagnb'er 3 and the flutter-valve 17 as described fon -the formillustrated in Figures 4 and 5 )theri7vise than as speci- & fied the construction and operation is the same as describedfor Figures 4 and 5. To provide for ready renewal of the chemical'inchamber 7 onerend of the'respirator" A .7 shell may beformed with a separable screw cap 25, as shown'inFigure 11.

Someoftheadvan'tages resulting froin'this 12 invention are/a gasl'nask containing a speak ing tube or voice transmitter that enables the v wearer to verbally or telephonically communicate with others; the elimination of in-' ternally contained valves in a maskwhich 1 0 also the readiness with which the mask is con-' vertible from the self contained type to the usual breathing tube type, or vice-versa, without alteration in the face-piece of the mask. The mask is particularly serviceable for use in industrial plants where it is essential that workmen be able to converse with one another or over the telephone, and also for use by firemen or policemen where the ability to communicate one with the other is most important.

I have described with particularity the preferred details of the several parts but it is to be understood that changes may be made therein and essential features of the invention retained.

' respirator Having described my invention and set forth its merits what I claim is:

1. A gas mask comprising a face-piece, a respirator embodying a chamber for passage of air to the interior of the face-piece and a chamber for voice transmission, encircled by the first mentioned chamber and a gas impervious diaphragm positioned to set-up voice vibrations in the voice transmission chamber and exclude the passage of air from said chamber to the interior of the face-piece.

2. A gas mask comprising a face-piece, a respirator embodying a chamber for voice transmission, and a chamber at the end thereof and in communication therewith and with the interior of the face-piece and formed with a diaphragm seat, and a gas-impervious diaphragm positioned on said seat to set-up voice vibrations in the voice transmission chamber and exclude the passage of air from said chamber to the interior of the facepiece.

3. Agas mask comprising a face-piece, a embodying a chamber for passage of air and a voice transmission chamber, a

7 member attached to the face-piece and havinterior of the face-piece,

ing an inwardly extending flange to forman airchamber between the member and flange in communication with the interior of the face-piece, and a diaphragm seated of purified air positioned about flange in communication with the interior of the face-piece and with the first mentioned air chamber, and a diaphragm seated against said flange to exclude'passage of air from the voice transmission chamber to the interior of the face-piece, said diaphragm being extended beyond the voice transmission chamber to form a valve controlling the flow of air from the respirator into the interior of the face-piece.

5. A gas mask comprising a face-piece, a respirator embodying a chamber for the passage of air, and a voice transmission chamber, encircled by the first mentioned chamber, a diaphragm positioned to exclude air from the voice transmission chamber into the interior of the face-piece, and means for attachment of the respirator to the facepiece.

-6. A gas mask comprising a face-piece, an open ended voice transmission chamber, a gas-impervious vibratory tioned within said voice transmission chamber to set up sound vibrations therein and to exclude passage of gas to the interior of the face-piece, an air chamber for the passage and encircling said voice transmission chamber, an annular air chamber adjacent the inner end of said first mentioned air chamber and communicating therewith and having an opening in its upper part communicating with the interior 'of the face-piece,

In testimony whereof I aflix'my signature.

LEWIS M. MCBRIDE.

a chamber for passage of air against said flange to exclude passage of transmission chamber to the air chamber of the respirator communicating with the air chamber formed by the flange.

4:. A gas mask comprising a face-piece, a respirator embodying a chamber for passage of air and a voice transmission chamber, a member attached to the face-piece and having an inwardly extending flange to form air from the voice an air chamber between the member and diaphragm posi- 

